The influence of right frontotemporal dysfunction on social behavior in frontotemporal dementia

BACKGROUND

Frontotemporal dementia (FTD) is associated with a variety of cognitive and behavioral dysfunctions. Symptoms may be influenced by the relative involvement of the right versus the left hemisphere, with left-sided FTD manifesting language changes and right-sided FTD presenting with aggressive, antisocial, and other socially undesirable behaviors.

OBJECTIVE

To test the hypothesis that right-sided FTD is associated with socially undesirable behavior.

METHODS

The authors assessed 41 patients with FTD diagnosed by the new research criteria for FTD(1) including behavioral, neuropsychologic, and neurologic testing as well as SPECT and MRI. Based on visual inspection of SPECT scans, 12 patients were classified as having predominantly right-sided and 19 patients were classified as having predominantly left-sided FTD. A clinician blinded to the imaging data reviewed medical records to tabulate the frequency of the following socially undesirable behaviors: criminal behavior, aggression, loss of job, alienation from family/friends, financial recklessness, sexually deviant behavior, and abnormal response to spousal crisis.

RESULTS

Eleven of 12 right-sided and 2 of 19 left-sided FTD patients had socially undesirable behavior as an early presenting symptom (chi = 23.3, p < 0.001).

CONCLUSION

The authors conclude that right-sided frontotemporal degeneration is associated with socially undesirable behavior. The early presence of socially undesirable behavior in FTD differentiates right-sided from left-sided degeneration. The results highlight the importance of the right hemisphere, especially frontotemporal regions, in the mediation of social behavior. The potential mechanism for these social losses with right-sided disease is discussed.

Motion analysis

BACKGROUND

The ability to make an objective evaluation of a surgeon's operative ability remains an elusive goal. In this study, we used motion analysis as a measure of dexterity in the performance of a simulated operation.

METHODS

Fifteen surgeons performed a total of 45 laboratory-based laparoscopic cholecystectomies on a cadaveric porcine liver model. Subjects were assigned to one of three groups according to their level of experience in human laparoscopic cholecystectomy. Electromagnetic tracking devices were used to analyze the surgeon's hand movements as they performed the procedure. Movement data (time, distance, number of movements, and speed of movement) were then compared.

RESULTS

Analysis of variance (ANOVA) movement scores across the three groups showed significantly better performance among the experienced laparoscopic surgeons than the novices. Learning curves across repetitions of procedures were plotted. Novices made more improvement than experts.

CONCLUSIONS

Motion analysis provides useful data for the assessment of laparoscopic dexterity, and the porcine liver model is a valid simulation of the real procedure.

Characterizing Magnetoencephalographic Spike Sources in Children with Tuberous Sclerosis Complex

PURPOSE

Tuberous sclerosis complex (TSC) often causes medically intractable seizures. Magnetoencephalography (MEG) localizes epileptiform discharges. To evaluate the use of MEG spike sources (MEGSSs) for localizing epileptic zones in TSC patients, we characterized MEGSSs and correlated them to EEG and magnetic resonance imaging (MRI) results.

METHODS

We analyzed data from seven children who underwent prolonged video-EEG, MEG, and MRI. We classified MEGSSs as clusters (six or more spike sources, <or=1 cm between sources) and scatters (fewer than six spike sources regardless of distance between sources; sources with >1 cm between sources regardless of number of sources).

RESULTS

A single, unilateral cluster with additional scatters occurred in two patients; these predominantly lateralized dipoles correlated to prominent tubers on MRI and ictal/interictal EEG zones. Bilateral clusters with scatters existed in two patients; cluster locations partly overlapped multiple prominent tubers. These patients also had bilateral or diffuse interictal discharges, bilateral or generalized seizures, and changing seizure types and EEG findings. Only bilateral scatters occurred in three patients; scatters partly overlapped EEG interictal/ictal-onset regions; one patient had coexisting generalized seizures. In one patient with equally bilateral scatters, scatters overlapped a prominent tuber and interictal/ictal-onset zones in the right frontal region.

CONCLUSIONS

MEG contributes to information from EEG and MRI for localizing epileptogenic zones in children with TSC. A single cluster with scatters in a unilateral hemisphere predicts a primary epileptogenic zone or hemisphere; bilateral or multiple clusters indicate bilateral primary or potential epileptogenic zones; and bilateral scatters without clusters may indicate epileptogenic zones that are hidden within extensive areas of scattered MEGSSs.

Cluster analysis reveals at least three, and possibly five distinct handedness groups

Multivariate techniques have used data from hand preference questionnaires to group hand preference items, but no attempt has been made to date to use multivariate analyses to group individuals in terms of handedness groups. This study analyzed the responses of 645 subjects on the Waterloo 60-item handedness questionnaire with a cluster analysis (BMDP) in order to determine the grouping of individuals in terms of hand preference patterns. Five distinct handedness groups were recognized by this procedure and a Discriminant Function Analysis revealed a very high accuracy of assigning individuals to the five groups. A cluster analysis of a shorter 14-item questionnaire suggested three distinct handedness groups, and the degree of accuracy of assigning individuals to these groups was also very high. As is the case with all multivariate techniques in neuropsychology, the question of whether the clusters form meaningful groupings awaits an answer in terms of their different neuropsychological properties.

Do left-handed competitors have an innate superiority in sports?

This study assessed handedness distributions among (a) sporting competitors (n = 1,112) and nonsporting university students (n = 1,112), (b) sporting competitors engaging in interactive (n = 576) and in noninteractive sports (n = 536), and (c) sporting competitors engaging in direct interactive (n = 219) and indirect interactive (n = 357) sports. Chi-squared showed that there were statistically significant differences in proportions of left-handed persons in (a) sporting competitors and nonsporting university students, (b) sporting competitors engaging in interactive and noninteractive sports, (c) sporting competitors engaging in interactive sports and nonsporting university students, and (d) sporting competitors engaging in direct interactive and indirect interactive sports. It appears that left-handers are more common among those who engage in competitive manual activities. This superiority of the left-handers may be fully explained by a consideration of tactical or strategic factors associated with handedness during sporting interactions. The results with important implications for the measurement and evaluation of handedness are discussed in the light of the current findings on laterality.

Intellectual Prognosis of Status Epilepticus in Adult Epilepsy Patients: Analysis with Wechsler Adult Intelligence Scale-Revised

PURPOSE

Status epilepticus (SE) appears to cause cognitive dysfunction as well as other serious neurologic sequelae. To confirm whether SE produces a subsequent intellectual decline, we evaluated intellectual function prospectively in adult epilepsy patients with and without SE.

METHODS

Of 1,685 patients with epilepsy who underwent comprehensive neuropsychological testing in two national hospitals in Japan, 15 patients experienced an episode of SE afterward and underwent the second neuropsychological examination after the SE episode. Forty clinically matched patients with epilepsy, but without an episode of SE since their initial neuropsychological examination, were also reevaluated. We compared IQs and subscores from the Wechsler Adult Intelligence Scale-Revised between the two groups by repeated measures analysis of variance. In the patients who experienced an SE episode, SE-related variables (i.e., age at the SE episode and type and duration of SE) and epilepsy-related variables such as epilepsy type, lateralization of EEG abnormalities, the presence of mesial temporal sclerosis, and previous history of SE, were evaluated in relation to intellectual outcome.

RESULTS

Patients with SE, in comparison to those without SE, failed to show any significant post-SE intellectual decline. Furthermore, neither the SE-related variables nor the clinical characteristics were correlated with intellectual outcome.

CONCLUSIONS

Our findings suggest that SE does not lead to a significant intellectual decline in adult patients receiving treatment for epilepsy.

Neuronal complexity loss in interictal EEG recorded with foramen ovale electrodes predicts side of primary epileptogenic area in temporal lobe epilepsy: a replication study

PURPOSE

To investigate whether a correct lateralization of the primary epileptogenic area by means of neuronal complexity loss analysis can be obtained from interictal EEG recordings using semi-invasive foramen ovale electrodes. In a previous study with recordings from intrahippocampal depth and subdural strip electrodes it was shown that the dynamics of the primary epileptogenic area can be characterized by an increased loss of neuronal complexity in patients with unilateral temporal lobe epilepsy (TLE).

METHODS

Neuronal complexity loss analysis was applied. This analysis method is derived from the theory of nonlinear dynamics and provides a topological diagnosis even in cases where no actual seizure activity can be recorded. We examined interictal EEG recorded intracranially from multipolar foramen ovale electrodes in 19 patients with unilateral TLE undergoing presurgical evaluation.

RESULTS

The primary epileptogenic area was correctly lateralized in 16 of the 19 investigated patients. The misclassification of the side of seizure onset in three patients might be attributed to the larger distance between the foramen ovale electrodes and the mesial temporal structures as compared to intrahippocampal depth electrodes.

CONCLUSIONS

Our results confirm the previous findings and provide further evidence for the usefulness of nonlinear time-series analysis for the characterization of the spatiotemporal dynamics of the primary epileptogenic area in mesial temporal lobe epilepsy.

On the futility of using familial sinistrality to subclassify handedness groups

Annett's right shift model was used to show that presence of left-handedness in parents or grandparents is an extremely weak indicator of whether or not a person's handedness is influenced by genetic factors. Furthermore, where a genetic influence is present, familial sinistrality is only weakly related to underlying genotype. The usual rationale given for subdividing handedness groups according to familial sinistrality is logically indefensible.

Multivariate Neuropsychological Prediction of Seizure Lateralization in Temporal Epilepsy Surgical Cases

PURPOSE

Neuropsychological assessment can be of assistance in determining seizure lateralization in cases where EEG and MRI findings do not provide clear lateralizing data. While several studies have examined the lateralizing value of individual neuropsychological measures, clinicians are still in need of a statistically sound method that permits the incorporation of multiple neuropsychological variables to predict seizure lateralization in the individual patient.

METHOD

The present study investigated the lateralizing value of several commonly used neuropsychological measures in a large sample of patients (n = 217) who eventually underwent surgical resection to treat their epilepsy. Side of surgery was used to operationally define seizure lateralization. A comparison of the relative utility of a multivariate versus univariate approach to predict seizure lateralization was conducted in temporal epilepsy cases.

RESULTS

The results provide evidence for the incremental validity of neuropsychological measures, other than memory and IQ tests, in the prediction of seizure lateralization in patients with medically intractable epilepsy. These data indicate that a multivariate approach increases the accuracy of prediction of seizure lateralization for temporal lobe epilepsy cases.

CONCLUSION

This study supports the use of a multivariate approach using neuropsychological measures to predict seizure lateralization in temporal epilepsy surgical candidates. Regression formulas are provided to enhance the clinical utility of these findings.

EEG correlates of a paper-and-pencil test measuring hemisphericity

The present study examined the validity of the Preference Test (PT), a questionnaire that intends to measure the extent to which subjects rely on right-hemisphere and left-hemisphere cognitions. Normal subjects (N = 20) completed the PT and were then assigned to a group with a relatively strong preference for left-hemisphere cognitions or a group with a relatively strong preference for right-hemisphere cognitions. Next, background EEG was recorded. Subjects with a preference for right-hemisphere cognitions were found to display relatively more alpha power over the left than over the right frontal areas, compared to subjects with a preference for left-hemisphere cognitions. This finding provides partial support for the validity of the PT.

Prevalence and handedness correlates of recurrent aphthous stomatitis in the Turkish population

OBJECTIVES

The present study was designed to determine the relationship between recurrent aphthous stomatitis (RAS) and handedness, and to assess the prevalence of RAS in the Turkish population.

METHODS

The present study was conducted among 11,360 persons (5,705 males and 5,655 females) with a mean age of 30.4 years. A questionnaire focusing on handedness was administered to these patients. Handedness was assessed according to the Edinburgh Handedness Inventory. The diagnosis of RAS was made on the basis of clinical appearance, location, and the patient's health history. RAS information of patients was collected by means of a data form specifically designed for this study. Subjects were informed about RAS. We took anamneses and filled out the investigation forms. Apart from patients with registration of current aphthae (average point prevalence, APP), patients who had a past two-year history (self-reported two-year prevalence, SRTP) of the lesion were also included in this study. Data were analyzed using the chi-square and logistic regression tests.

RESULTS

The prevalence of RAS (APP) was 2.7 percent and that of a history of RAS (SRTP) 22.8 percent. Thus, the total prevalence (APP+SRTP), including present lesions and a two-year history (SRTP), was 25.5 percent. Adjusted results showed that females, left-handers, 10-30-year-olds, and nonsmokers were 1.53, 1.69, 2.05, and 1.61 times more likely to have RAS (APP+SRTP) than males, right-handers, 31-50-year-olds, and smokers, respectively (P<.0001).

CONCLUSION

The present study suggests that left-handedness appears to be a predictor factor for RAS.

Unilateral cleft lip with or without cleft palate and handedness: is there an association?

OBJECTIVE

The purpose of this study was to investigate the possibility of a relationship between the side of occurrence of unilateral clefting of the lip and/or palate and handedness, also taking into account the type of the initial cleft condition, a factor that has not been adequately assessed in previous studies.

DESIGN

This was a retrospective study.

SETTING

Division of Orthodontics, The Hospital for Sick Children, Toronto, Canada, and Cleft Lip and Palate Program, Children's Hospital, Winnipeg, Canada.

PARTICIPANTS

Subjects were 289 patients (176 males and 113 females) 9 years of age or older presenting with a history of unilateral clefts of the lip with or without the palate. Of these patients, 217 were recruited from the patient pool of the Orthodontic Clinic at the Hospital for Sick Children in Toronto. The remaining 72 were selected from the registry of the Cleft Lip and Palate Program of the Children's Hospital in Winnipeg. Any syndromic cases were excluded from the sample.

MAIN OUTCOME MEASURES

Assessment of handedness was performed by asking the patients to fill out a multi-item questionnaire in which patients were asked to identify which hand they would use for different tasks. The side and type of the initial cleft condition were identified by reviewing each patient's hospital chart and by cross-referencing with clinical examination. Statistical evaluation of the results was performed by using the chi-square test.

RESULTS

There was a significantly larger number of left-sided clefts (198) in the sample than right-sided clefts (91), (p < .001). The proportion of left-sided clefts among left-handers (84.6%) was higher than that among right-handers (66.8%). However, the relationship between side of cleft and handedness was not statistically significant (p = .185). Clefts of the primary palate only seemed to occur on the left side 3.5 times more often than on the right, whereas the corresponding ratio of left:right manifestation for clefts of the primary and secondary palate was 1.8:1. The difference was statistically significant (p < .05).

CONCLUSION

The findings of this study confirm the affinity of unilateral clefts for the left side but suggest that there are differences between clefts of the primary palate only and clefts of the primary and secondary palate. Also, non-right-handed patients show a greater predilection for having a cleft on the left side than do right-handed patients.

Consistency of hand use and accidents with injury

In this study, we examined the relationship between the consistency of hand use and the self-reported incidence of accidents with injuries which required medical care in groups of university students (n = 23 for each group). To do this, we adopted a scoring procedure for the Briggs-Nebes Handedness Scale that permitted us to classify individuals as consistent or inconsistent in the use of their hands. We observed that the inconsistent group was 6.12 times more likely to have experienced accidents with injury that required medical care than the consistent group. These data have implications for the literature on handedness classification and accidents. Collectively, these limited data underscore the need to pay attention to the consistency of hand use in research on handedness, health, and longevity.

Urine patterns, peptide levels and IgA/IgG antibodies to food proteins in children with dyslexia

There is an association between psychiatric disorders and dyslexia. In some psychiatric disorders abnormal urinary peptide patterns and peptide levels, and elevated levels of IgA antibodies to food proteins have been detected. These abnormalities are probably due to insufficient breakdown of the proteins gluten and casein. The aim of this study was to discover whether such abnormalities could be found in urine samples and serum of children with dyslexia. After screening 291 pupils in the fourth grade, 15 dyslexics and 15 controls were pairwise matched by gender, age, and cognitive level. Word decoding, spelling, and short-term memory tests were carried out, and information on handedness, immune and other disorders was obtained. Analyses of 24-h urine samples and of serum were performed. The reading abilities significantly differentiated the groups, and significant differences were found in frequency of left-handedness, immune disorders and other disorders. Three dyslexic children had elevated IgA antibodies. Two of these had positive endomycium tests, and coeliac disease was confirmed by biopsy. One had antibodies to proteins in milk. Our findings may suggest weak urinary peptide abnormalities in the dyslexic children, and they show significant differences in levels of IgA of antibodies to food proteins.

Axonal bias at a representational border in adult rat somatosensory cortex (S1)

The cortex is a highly organized structure and this organization is integral to cortical function. However, the circuitry underlying cortical organization is only partially understood, thus limiting our understanding of cortical function. Within the somatosensory cortex, organization is manifest as a map of the body surface. At the level of the cortical circuitry the horizontal connections of Layer 2/3 express a physiological bias that reflects discontinuities within the somatosensory map. Both excitation and inhibition are smaller when evoked from across a representational border, as compared to when they are evoked from within the representation. This physiological bias may be due to a bias in either the strength or number of synapses and/or the number of axons that cross this border and the extent of their arborization. In this study we used both an anterograde (Phaseolus vulgaris leucoagglutinin) and a retrograde (cholera toxin B) tracer to examine Layer 2/3 horizontal projections in rat S1. We determined that there is a bias in the amount of horizontal axonal projections that cross the forepaw/lower jaw border as compared to projections remaining within an individual representation. This bias in axonal projection and the correlated bias in excitation and inhibition may underlie the expression of the representational border.

Consistency of hand use and sleep problems

In this study, we measured the relationship between the consistency of hand use and three symptoms of insomnia, i.e., delayed sleep onset, frequent awakenings during sleep, and trouble returning to sleep after an awakening. For each of these insomnia-related symptoms, university students who were classified as inconsistent in the use of their hands (n = 30) were significantly more likely to report problems than their consistent hand-use peers (n = 30). These data were discussed both in relation to the literature on handedness classification and sleep problems and the emerging literature on consistency of hand use and health-related problems.

Location of the epileptic zone and its physiopathological effects on memory-related activity of the temporal lobe structures: a study with intracranial event-related potentials

PURPOSE

Neuropsychological research with epileptic patients has suggested that the location of seizure focus may be an important variable determining the nature and severity of memory impairments. According to this assumption, this study was designed to investigate the effects of the location of the epileptic zone on the memory-related activity recorded directly from different temporal lobe structures.

METHODS

Intracranial event-related potentials (ERPs) were recorded during a continuous recognition memory task, which is known to elicit the modulation of N400 and P600 components (i.e., the ERP old/new effect). The patients were separated into three groups according to the location of their epileptic zone: unilateral temporal (UTE), temporal plus extratemporal (TEE), and bitemporal (BTE). Recordings were obtained from three temporal lobe structures: hippocampus, amygdala, and lateral temporal cortex.

RESULTS

The results showed that in the hippocampus, the ERP old/new effect was abolished in the TEE group only. In the amygdala, although largely unaffected, the ERP modulation appeared to be more impaired in UTE patients. Contrasting with these data is the observation that the magnitude and reliability of the ERP old/new effect recorded at the neocortical level increases as the epileptic zone extends to the temporal lobes (i.e., BTE>TEE>UTE).

CONCLUSIONS

It is concluded that the memory-related activity modulation of memory ERPs recorded from different temporal lobe structures is affected differently by the presence of an epileptic zone as a function of its location. The possible clinical implications of these findings in surgery planning are also discussed.

Hand preference as related to development and behavior in infancy

55 healthy infants were assessed for their developmental and behavioral patterns at the age of 9 mo. Hand preference was assessed at 20 mo. of age. The distribution of hand preference showed 12 were right-handed, 11 left-handed and 23 ambidextrous. This distribution appears shifted more to the left than that reported for older children. Although their data were based on different tests not appropriate for 9-mo.-old infants, ambidexterity appeared to reflect part of the hand-preference continuum. No significant relationship between hand preference and developmental attainments was noted. Perhaps a larger sample would provide a clear developmental behavioral pattern and hand preference in infancy.

Inventory-derived task handedness preferences of nine professions and their associations with self-report global handedness preferences

The handedness preference (laterality) of 1,196 professionals grouped in nine professions previously reported using self-reported global handedness and scores on a modified Edinburgh Handedness Inventory was further defined by evaluating the association between profession and the 10 manual tasks of the inventory. The previously reported ranking of professions in order of increasing righthandedness of laterality score arose from the handedness of specific inventory tasks. A similar association was found for self-reported global handedness. The evidence continues to support the hypothesis of an association between handedness preference and specific aptitudes or skills in this sample of professional persons.

Measuring familial sinistrality: Problems with dichotomous classification

Familial sinistrality (FS), or familial left-handedness, is usually measured as a presence/absence dichotomy (FS+/FS-). Measuring FS as a dichotomy is problematic in at least two ways: (1) magnitude data are discarded and (2) there is an increased risk of violating statistical assumptions. We hypothesised that using a non-dichotomised FS measure would allow more sensitive statistical tests than using a dichotomised measure. The non-dichotomised measure examined was proportion of family that is left-handed, or Proportional FS (FSP). FS measures of 60 healthy adults were consistent with our hypothesis: (1) The effect size was 2.3 times larger when FSP was used than when Dichotomised FS (FSD) was used; (2) the observed relationship was statistically significant when FSP was used but not when FSD was used; and (3) statistical assumptions were violated when FSD was used but not when FSP was used. When cases were weighted to account for an increased likelihood of FS in large families, results were similar. Next, bootstrapping methods were used to estimate empirically the long-term differences in power between analyses incorporating FSP and those incorporating FSD. Using FSP was associated with long-term increases in both power and effect size of over 50% relative to using FSD. We conclude that using a proportional rather than a dichotomous measure of FS will enhance the accuracy of observed effect sizes, increase the sensitivity of statistical tests, and reduce the likelihood of violating statistical assumptions.

Handedness and stress-related health problems

Response of groups of 163 right-, 22 mixed-, and 20 left-handed university students to the seven symptom subscales of a 48-item Stress-related Health Problems Scale were used to test the hypothesis that left-handedness is associated with an increased risk of stress-related health problems. Since only one of the 21 possible statistical tests computed barely reached statistical significance, there is no meaningful relationship between handedness and stress-related health problems.